Introduction
Dr. Sanjay Vaid, M.D.
Ultrasonography is a medical diagnostic technique in which very high frequency sound is aimed into the body. An ultrasound scanner sends pulses into a patient’s body through a transducer. These waves are alternated varyingly by the tissues of the body and a string of return echoes are processed by a computer to display a continuous real–time image on a monitor.

Clinical applications of Ultrasonography

• Routine abdominal/pelvic examination.
• Obstetric and gynecological examinations.
• Neonatal brain & infant spine.
• Musculoskeletal and skin.
• Small part sonography scrotum, penis, breast thyroid / parathyroid / neck eye salivary glands transvaginal
• Intra operative Endo USG
  • Trans–rectal
  • Trans–oesophageal
  • Endovascular
• USG guided interventional techniques

Safety of diagnostic ultrasound
The increasing widespread use of diagnostic ultrasound techniques means that safety consideration have became more important especially in obstetric and neonatal applications.Though the biological effects, including cavitations (formation of vacuum) caused by ultrasound have been extensively researched, no conclusive evidence has been produced in any epidemiological study to show that ultrasonography can produce any abnormalities in a fetus or neonate.

However, a few general recommendations should be made to ensure continued safe use of US.

1. Low output power and high receiver gain of US machine being used.
2. Minimum contact time of transducer with skin.
3. Minimum acoustic output with maximum diagnostic accuracy and performance.

Common indications for ultrasonography

• Obstetric USG – pregnancy scan.
• Scrotum and penis ultrasound to study.
• Eye.
• Thyroid/Parathyroid.
• Neck.
• Salivary glands.
• Breast.
• Neonatal brain.
• Infant.
• Spine.
• Musculoskeltal system.
• Skin and soft tissues.
• Intraoperative USG.
• Endo USG.
• USG guided procedures.